Method of producing elemental sulphur



Nov. 13 1923.

C. s. FOGH METHOD OF PRODUCING 'ELEMENTAL SULPHUR Filed Oct. 23, 1920 NJ g i w =0 -J m I w M .lu m u I m M Q F I 1 w L m N N w n m n 14 m m Naffozncl rd Patented Nov. 13, 1923.

UNITED. STATES ammo Application filed October 23, 1920. SerialItfo.419,021.

To all whom it may concern:

Be it known that I, CARL S. Form, a subect of the King of Denmarkresiding at hiladel hia, in the county of lhiladelphia and State ofPennsylvania, have invented certain new and useful Improvements inMethods of Producing Elemental Sulphur, of which the following is aspecification.

My invention relates to the recovery of elemental sulphur from sulphideores or other sulphur-bearing material from which the sulphur may bevolatilized by heat alone.

It has for its object not only to recover sulphur but to assist in theelimination of the sulfurous fume nuisance by avoiding, to a mate-rialextent, the production of such fumes.

Many sulfide ores have a pyrite (Fes content, from which one atom ofsulphur can be volatilized by heat alone. There are also found certaindeposits where elemental sulphur is physically combined with a siliceousgangue. My process is applicable to either of such products.

The process comprises continuously feeding the material from which thesulphur 1s to be eliminated into and through a practically gas-tightmechanically rabbled roasting furnace preferably of the mulxl zplehearth type, such as the well-known edge furnace. As the material passesover the hearths of the furnace, it is subjected to hot gases containingpractically no free oxygen, and in such volume and at such temperaturethat the sulphur will be volatilized. The gases evolved from the furnaceare passed through a suitable dust-separator and the cleaned gas is thenpassed through a suitably cooled chamber or condenser in which thesulphur is condensed and vcollected either as brimstone or flowers ofsulphur. The residual ases from the condenser are then passed through aheater within which they are heat ed to the requisite temperature andagain introduced into the furnace. Suitable flues and fans are providedfor maintaining the continuous circulation of the gases through thesystem.

A diagrammatic representatlon of a plant for carrying out the process isshown in the accompanying-drawing in which 1 is a multiple hearth,I'oastin furnace provided with a hopper 2 for intro ucmg the ore, adelivery chute 3, and mechanism 4, for operating the stirrer arms. Thegases pass from the furnace through flue 5 to a dust arrester, 6, fromwhich the gases pass by flue 7 to the condenser, 8, wherein the sulphuris condensed and removed through discharge chute 9.

From the condenser, the residual gases pass through flue 10, fan 11 andflue 12 to a water or heat interchanger, here shown as a chamber 13encircling the pipe 14, which may be heated by any suitable means suchas an oil, gas, or coal burner. From the chamber 13, the hot gases passinto flue 15 and thence by one or more pipes 16 into one or more of thehear-tbs of the furnace 1.

In starting the operation of such a plant, the furnace is heated andstarted in the same manner as is now done in smelter practice, and ofcourse S0 and S0 gases will be formed, which are circulated system untilthe oxygen in the-system has been practically exhausted, when thetemperature of the gases is raised by the heater to a point which willvolatilize the sulphur from the ore or sulphur-bearing material beingfed through the furnace. This sulphur vapor is carried by thecirculating gases to the condensing chamber in which it is precipitated,and the non-oxygen-bearing gases are again circulated through the heaterand furnace.

The process is therefore continuous. The raw material is continuouslyfed to the furnace. The residual material is continually dischargedtherefrom, and the sulphur vapor is produced by the continuouscirculation of the heating gases. This method avoids the diflicultiesincident to operating muflle fired furnaces, and obviates the objectionsto batch processes or operation of retorts. It has the further advantagethat it provides for the treatment of large tonnages of material, anessential requisite in most smelting plants.

What I claim is:

1. The continuous process of volatilizing sulphur fromsulphur-containing materials which consists in heating such material,during its passage through a gas-tight mechanically rabbled furnace, bycontact with nonoxidizing gases heated to temperature suflicient tovolatilize sulphur removing the gases carrying sulphur vapor from thefurnace in continuous flow, separating out any dust particles therefrom,condensing the sulphur from said gases, reheating the residual ases to asuflicient temperature to cause volatilize: tion of sulphur from thematerial passing through the through the furnace, and passing suchheated gases into the furnace.

2. The continuous process of volatilizing sulphur fromsulphur-containing materials which consists in heating such material,cluring its passage through a gas-tight mechanically rabbled furnace, bycontact with nonoxidizing gases heated to temperature sufiicient tovolatilize sulphur removing the gases carrying sulphur vapor from thefurnace in continuous flow, condensing the sulphur from said gases,reheating the residual gases to a sufficient temperature to causevolatilization of sulphur from the material passing through the furnace,and passing such. heated gases into the furnace.

3. The continuous process of "rolatilizing sulphur from pyritecontaining ores which consists in heating such material, during itspassage through a gas-tight mechanically rahhled furnace, by contactwith non-oxidizing gases heated to temperature sufiicient to volatilizeone atom of sulphur, removing the gases carrying sulphur vapor from thefurnace in continuous flow, condensing the sulphur from said gases,reheating the residual gases to a sufiicient temperature to" causevolatilization of sulphur from the material passing through the furnace,and passing such heated gases into the furnace.

In testimony whereof, I afiix my si nature;

- CARL S. F GE;

